Merge pull request #693 from SaberUK/insp20+modulemanager-bugs

[2.0] Fix various problems with ModuleManager.
Fix ACCEPT propagation bug when it got a nick prefixed with +

Fixes #696
Does not apply to 2.2 due to Attila's rewrite of the module
m_override refused to override if the user held halfop or higher in the channel they wanted to override